Pyrrhus: No law demands mercy to prisoners
Agamemnon: Though the law forbids it not, yet decency forbids it.
Pyr: The victor is at liberty to do whatever he likes.
Agam.: To whom much is allowed, it is least suitable to act wantonly.

English translations of quotes in this section by Richard Mott Gummere except as otherwise noted

What man can you show me who places any value on his time, who reckons the worth of each day, who understands that he is dying daily?

Letter I: On Saving Time

For we are mistaken when we look forward to death; the major portion of death has already passed. Whatever years be behind us are in death's hands.

Letter I: On Saving Time

Sera parsimonia in fundo est.

It is too late to spare when you reach the dregs of the cask.

Letter I: On saving time, line 5

This quote is often directly attributed to Seneca, but he is referring to lines 368-369 of Works and Days by the Greek poet Hesiod : Take your fill when the cask is first opened and when it is nearly spent, but midways be sparing: it is poor saving when you come to the lees. (translated by Hugh G. Evelyn-White)

Alternate translation: Thrift comes too late when you find it at the bottom of your purse. (translator unknown)

Alternate translation: It is too late to be thrifty when the bottom has been reached. (translator unknown).

Of course, however, the living voice and the intimacy of a common life will help you more than the written word. You must go to the scene of action, first, because men put more faith in their eyes than in their ears, and second, because the way is long if one follows precepts, but short and helpful, if one follows patterns.

Letter VI: On precepts and exemplars, line 5.

Alternate translation: Teaching by precept is a long road, but short and beneficial is the way by example.

Remember, however, before all else, to strip things of all that disturbs and confuses, and to see what each is at bottom; you will then comprehend that they contain nothing fearful except the actual fear.

Letter XXIV: On despising death, line 12

Alternate translation: You will understand that there is nothing dreadful in this except fear itself. (translator unknown).

Nam qui peccare se nescit, corrigi non vult.

If one doesn't know his mistakes, he won't want to correct them.

Letter XXVIII: On travel as a cure for discontent, line 9

Alternate translation: The knowledge of sin is the beginning of salvation (translated by Richard M. Gummere).

Kindly remember that he whom you call your slave sprang from the same stock, is smiled upon by the same skies, and on equal terms with yourself breathes, lives and dies. It is just as possible for you to see in him a free-born man as for him to see in you a slave.

Letter XLVII: On master and slave, line 10.

sic cum inferiore vivas quemadmodum tecum superiorem velis vivere.

Treat your inferiors as you would be treated by your betters.

Letter XLVII: On master and slave, line 11

This can be related to other expressions on the ethics of reciprocity, often referred to as the variants of the Golden Rule.

We are mad, not only individually, but nationally. We check manslaughter and isolated murders; but what of war and the much-vaunted crime of slaughtering whole peoples? There are no limits to our greed, none to our cruelty. And as long as such crimes are committed by stealth and by individuals, they are less harmful and less portentous; but cruelties are practised in accordance with acts of senate and popular assembly, and the public is bidden to do that which is forbidden to the individual. Deeds that would be punished by loss of life when committed in secret, are praised by us because uniformed generals have carried them out. Man, naturally the gentlest class of being, is not ashamed to revel in the blood of others, to wage war, and to entrust the waging of war to his sons, when even dumb beasts and wild beasts keep the peace with one another. Against this overmastering and widespread madness philosophy has become a matter of greater effort, and has taken on strength in proportion to the strength which is gained by the opposition forces.

But how much more highly do I think of these men! They can do these things, but decline to do them. To whom that ever tried have these tasks proved false? To what man did they not seem easier in the doing? Our lack of confidence is not the result of difficulty. The difficulty comes from our lack of confidence.

Also translated as: It is not because things are difficult that we do not dare, but because we do not dare, things are difficult.

The cause of anger is the belief that we are injured; this belief, therefore, should not be lightly entertained. We ought not to fly into a rage even when the injury appears to be open and distinct: for some false things bear the semblance of truth. We should always allow some time to elapse, for time discloses the truth.

De Ira (On Anger): Book 2, cap. 22, line 2

Alternate translation: Time discovers truth. (translator unknown).

fidei acerrimus exactor est perfidus

No man expects such exact fidelity as a traitor.

De Ira (On Anger): Book 2, cap. 28, line 7.

Magna pars hominum est quae non peccatis irascitur, sed peccantibus.

A large part of mankind is angry not with the sins, but with the sinners.

We are all chained to fortune: the chain of one is made of gold, and wide, while that of another is short and rusty. But what difference does it make? The same prison surrounds all of us, and even those who have bound others are bound themselves; unless perchance you think that a chain on the left side is lighter. Honors bind one man, wealth another; nobility oppresses some, humility others; some are held in subjection by an external power, while others obey the tyrant within; banishments keep some in one place, the priesthood others. All life is slavery. Therefore each one must accustom himself to his own condition and complain about it as little as possible, and lay hold of whatever good is to be found near him. Nothing is so bitter that a calm mind cannot find comfort in it. Small tablets, because of the writer's skill, have often served for many purposes, and a clever arrangement has often made a very narrow piece of land habitable. Apply reason to difficulties; harsh circumstances can be softened, narrow limits can be widened, and burdensome things can be made to press less severely on those who bear them cleverly.

That man lives badly who does not know how to die well.

Should I be surprised that dangers which have always surrounded me should at last attack me? A great part of mankind, when about to sail, do not think of a storm. I shall never be ashamed of a reporter of bad news in a good cause.

Variant translation: I shall never be ashamed of citing a bad author if the line is good.

Virtue runs no risk of becoming contemptible by being exposed to view, and it is better to be despised for simplicity than to be tormented by continual hypocrisy.

Our minds must have relaxation: rested, they will rise up better and keener. Just as we must not force fertile fields (for uninterrupted production will quickly exhaust them), so continual labor will break the power of our minds. They will recover their strength, however, after they have had a little freedom and relaxation.

Whether we believe the Greek poet, "it is sometimes even pleasant to be mad", or Plato, "he who is master of himself has knocked in vain at the doors of poetry"; or Aristotle, "no great genius was without a mixture of insanity"; the mind cannot express anything lofty and above the ordinary unless inspired. When it despises the common and the customary, and with sacred inspiration rises higher, then at length it sings something grander than that which can come from mortal lips. It cannot attain anything sublime and lofty so long as it is sane: it must depart from the customary, swing itself aloft, take the bit in its teeth, carry away its rider and bear him to a height whither he would have feared to ascend alone.

In Latin, nullum magnum ingenium sine mixtura dementiae fuit (There is no great genius without some touch of madness). This passage by Seneca is the source most often cited in crediting Aristotle with this thought, but in Problemata xxx. 1, Aristotle says: 'Why is it that all those who have become eminent in philosophy or politics or poetry or the arts are clearly melancholic?' The quote by Plato is from the Dialogue Phaedrus (245a).

Death is a release from and an end of all pains: beyond it our sufferings cannot extend: it restores us to the peaceful rest in which we lay before we were born. If anyone pities the dead, he ought also to pity those who have not been born. Death is neither a good nor a bad thing, for that alone which is something can be a good or a bad thing: but that which is nothing, and reduces all things to nothing, does not hand us over to either fortune, because good and bad require some material to work upon. Fortune cannot take ahold of that which Nature has let go, nor can a man be unhappy if he is nothing.

From Ad Marciam De Consolatione (Of Consolation, To Marcia), cap. XIX, line 5

Nothing lasts forever, few things even last for long: all are susceptible of decay in one way or another; moreover all that begins also ends.

From Ad Polybium De Consolatione (Of Consolation, To Polybius), chap. I; translation based on work of Aubrey Stewart

magna servitus est magna fortuna.

A great fortune is a great slavery.

From Ad Polybium De Consolatione (Of Consolation, To Polybius), chap. VI, line 5

Shun no toil to make yourself remarkable by some talent or other; yet do not devote yourself to one branch exclusively. Strive to get clear notions about all. Give up no science entirely; for science is but one.

[Seneca] would have denounced the opinion to which most philosophers, tacitly or otherwise, have come round in the last half-century, that it is no part of the business of philosophy to turn people into better persons, as tantamount to desertion or lèse-majesté.

Robin Campbell, introduction to Seneca's Letters

[Seneca’s] tremendous faith in philosophy … was grounded on a belief that her end was the practical one of curing souls, of bringing peace and order to the feverish minds of men pursuing the wrong aims in life.

Robin Campbell, introduction to Seneca's Letters

He is refreshingly undogmatic, incomplete, and at times even senile. We cannot rightly accuse him of all the moralizing and dogmatism which spoiled the objective accuracy of medieval Science before Roger Bacon. Nor can we blame him for assuming that imprisoned air is the main agency in earthquakes, or for not knowing that the rainbow's colors are the result of decomposition of white light instead of a seeming color which does not really exist, or for believing that lightning melts metals and freezes wine, or that the sun is supported by exhalations from the earth. In his assumption, however, that comets may have orbits which carry them beyond the zodiac, that there is an evolutionary process in the world, and that rings round the sun are often the result of atmospheric conditions, he is sound. But after all, how accurate were the astronomers before Galileo, the physicists before Newton, or the biologists before Darwin? Seneca's guesses are as good as those of any other speculator before the discoveries of modern Science.

Seneca's virtue shows forth so live and vigorous in his writings, and the defense is so clear there against some of these imputations, as that of his wealth and excessive spending, that I would not believe any testimony to the contrary.

Religion is regarded by the common people as true, by the wise as false, and by rulers as useful.

As quoted in What Great Men Think About Religion (1945) by Ira D. Cardiff, p. 342. No original source for this has been found in the works of Seneca, or published translations. It is likely that the quote originates with Edward Gibbon who wrote:

Has been attributed to Seneca since the 1990s (eg. Gregory K. Ericksen, (1999), Women entrepreneurs only: 12 women entrepreneurs tell the stories of their success, page ix.). Other books ascribe the saying to either Darrell K. Royal (former American football player, born 1924) or Elmer G. Letterman (Insurance salesman and writer, 1897-1982). However, it is unlikely either man originated the saying. A version that reads "He is lucky who realizes that luck is the point where preparation meets opportunity" can be found (unattributed) in the 1912 The Youth's Companion: Volume 86. The quote might be a distortion of the following passage by Seneca (who makes no mention of "luck" and is in fact quoting his friend Demetrius the Cynic):

"The best wrestler," he would say, "is not he who has learned thoroughly all the tricks and twists of the art, which are seldom met with in actual wrestling, but he who has well and carefully trained himself in one or two of them, and watches keenly for an opportunity of practising them." --- Seneca, On Benefits, vii. 1

Every new beginning comes from some other beginning's end.

This line was popularized by Semisonic in their hit "Closing Time," and has been widely attributed to Seneca (though also attributed to Anonymous, and Traditional Roman Proverb).